DOUBLE BUBBLE Two enormous bubbles sandwich the Milky Way and emit gamma rays (illustrated). Two chimneys that glow in X-rays seem to connect these bubbles to the galaxy’s center, scientists report.

NASA Goddard Space Flight Center

MOMMY BIRD This ancient avian, named Avimaia schweitzerae, lived about 110 million years ago in what is now northwestern China. Analyses of the fossil revealed that the bird’s body contained an unlaid egg (lighter brown smudge) when it died.

A.M. Bailleul et al/Nature Communications 2019

KILLER CAT No Beast So Fierce tells the story of the “Man-Eater of Champawat,” a tiger that terrorized parts of India and Nepal in the early 1900s (a tiger in India’s Nagzira Wildlife Sanctuary is shown).

HIDDEN FROM VIEW With a brown back, orange tummy and glittery bluish-white spots that help it blend in with the forest floor, the newly described starry dwarf frog (pictured) stayed hidden from scientists for centuries.